Another vote for the PMAS here, I got a 75mm for my 30#'s and the car idles wonderfully, no surging or hunting. Smooth all the way through the power band and A/F didn't spike or drop out on the wideband from 1000-6400 rpm. I'd recommend one to anyone.
also, on the tuning, I did tune mine by FP and timing for now but I intend to buy a Tweecer R/T when the finances get a little better in line.